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Should I replace the TPMS sensors (or replace the batteries) - or bet that they will last another three years.

Can you replace the batteries - or do you need to buy new sensors?

All opinions welcomed.

The batteries can't be replaced (although DSX tried). There are various articles on how long the batteries will last, but reliable sources indicate that their life depends on driving mileage and years of service since the TPMS will go into "sleep mode" when not in use. I've seen articles that indicate 5 - 9 years of service...or 5 - 7 years of service depending on "use."

What was the build date of your car...we're now in the middle of 2013...are you a "high mileage" driver? Do you expect your tires to last THREE more years, as your TPMS are now 4.5 years old (depending on car build date).

Certainly, the batteries will "fail" according to a "normal curve," with high mileage, and cold climate users experiencing battery failures at a higher rate.

I'm thinking you'll be at the "edge" of TPMS replacement during the end of your new tire life, depending on annual mileage.

Car now has 71,000 miles. Build date was 3/2008. I am the first (only owner). Expectation is that the replacement tires (another set of Conti DWS) will last the same as the last set - that went 36,000 miles.

Car now has 71,000 miles. Build date was 3/2008. I am the first (only owner). Expectation is that the replacement tires (another set of Conti DWS) will last the same as the last set - that went 36,000 miles.

So if my calculations are correct...and in the "worst case scenario" of 7-year TPMS battery life, they may fail in 2015 near the end of your replacement tire life...if mileage remains the same. Hard to predict if this will be an accurate end of the TPMS battery life.

The batteries can't be replaced (although DSX tried). There are various articles on how long the batteries will last, but reliable sources indicate that their life depends on driving mileage and years of service since the TPMS will go into "sleep mode" when not in use. I've seen articles that indicate 5 - 9 years of service...or 5 - 7 years of service depending on "use."

What was the build date of your car...we're now in the middle of 2013...are you a "high mileage" driver? Do you expect your tires to last THREE more years, as your TPMS are now 4.5 years old (depending on car build date).

Certainly, the batteries will "fail" according to a "normal curve," with high mileage, and cold climate users experiencing battery failures at a higher rate.

I'm thinking you'll be at the "edge" of TPMS replacement during the end of your new tire life, depending on annual mileage.

You've brought back some memories P&G. I was able to replace the button batteries on the two types I experimented with but it wasn't cost effective. The battery, as well as the entire circuit board, is encapsulated in a firm gel or resin which is difficult to remove. Although the button batteries were common types the terminals were soldered to the circuit board.
Bottom line: Replacing batteries would cost me more in parts, direct labor, testing and warranty costs than I can buy the new sensors for.
If I were the OP I'd leave the sensors alone and take my chances. An interesting development is that we are starting to see battery failures, but not of all sensors on each car. Odd because they all have exactly the same run times. There are cars on which I changed a sensor a year ago and no others have failed since. All in all though, the battery life seems to be longer than first predicted, just like Prius hybrid batteries.